I spent some time doing some "research"

and developed a theory:
My Issues are not completely caused by the minimal warped records, they also relate to Mixvibes' Tracking/Decoding Algorithm!
- as I use an Audio4 DJ with Mixvibes I downloaded the Traktor Demo and gave it a try with one of these Mixvibes Vinyls. Even if the speed and timecode didn't match the Traktor signal, scratching was possible.
I thereby discovered that Traktor handled Skips and jumps in relative mode with an unsupported timecode way better (soundwise) than Mixvibes does for me.
- when scratching in absolute Mode in Mixvibes, fast scratches sound really horrible and the Software is often losing Track for some ms even when the Needle is not skipping!
I have no Latency Issues whatsoever and playing with the TC Threshold didn't help at all.
So I'm guessing that this is not the Standard Mixvibes behaviour and is somehow related to my System?